Adds fallbackUri to Hystrix filter

fixes gh-38
2018-01-08 16:34:54 -05:00
parent e117906db8
commit d634113acf
7 changed files with 138 additions and 68 deletions
--- a/docs/src/main/asciidoc/spring-cloud-gateway.adoc
+++ b/docs/src/main/asciidoc/spring-cloud-gateway.adoc
@@ -49,7 +49,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: after_route
        uri: http://example.org
        predicates:
@@ -68,7 +67,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: before_route
        uri: http://example.org
        predicates:
@@ -87,7 +85,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: between_route
        uri: http://example.org
        predicates:
@@ -106,7 +103,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: cookie_route
        uri: http://example.org
        predicates:
@@ -125,7 +121,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: header_route
        uri: http://example.org
        predicates:
@@ -144,7 +139,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: host_route
        uri: http://example.org
        predicates:
@@ -164,7 +158,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: method_route
        uri: http://example.org
        predicates:
@@ -183,7 +176,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: host_route
        uri: http://example.org
        predicates:
@@ -204,7 +196,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: query_route
        uri: http://example.org
        predicates:
@@ -220,7 +211,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: query_route
        uri: http://example.org
        predicates:
@@ -240,7 +230,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: remoteaddr_route
        uri: http://example.org
        predicates:
@@ -264,7 +253,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: add_request_header_route
        uri: http://example.org
        filters:
@@ -283,7 +271,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: add_request_parameter_route
        uri: http://example.org
        filters:
@@ -302,7 +289,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: add_request_header_route
        uri: http://example.org
        filters:
@@ -321,7 +307,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: hytstrix_route
        uri: http://example.org
        filters:
@@ -330,6 +315,28 @@ spring:

 This wraps the remaining filters in a `HystrixCommand` with command name `myCommandName`.

+The Hystrix filter takes an optional `fallbackUri` parameter. Currently, only `forward:` schemed URIs are supported. If the fallback is called, the request will be forwarded to the controller matched by the URI.
+
+
+.application.yml
+[source,yaml]
+----
+spring:
+  cloud:
+    gateway:
+      routes:
+      - id: hytstrix_route
+        uri: http://example.org
+        filters:
+        - name: Hystrix
+          args:
+            name: fallbackcmd
+            fallbackUri: forward:/fallbackcontroller
+
+This will forward to the `/fallbackcontroller` when the Hystrix fallback is called.
+----
+
+
 === PrefixPath GatewayFilter Factory
 The PrefixPath GatewayFilter Factory takes a single `prefix` parameter.

@@ -340,7 +347,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: prefixpath_route
        uri: http://example.org
        filters:
@@ -359,7 +365,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: preserve_host_route
        uri: http://example.org
        filters:
@@ -398,7 +403,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: requestratelimiter_route
        uri: http://example.org
        filters:
@@ -426,7 +430,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: prefixpath_route
        uri: http://example.org
        filters:
@@ -460,7 +463,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: removerequestheader_route
        uri: http://example.org
        filters:
@@ -479,7 +481,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: removeresponseheader_route
        uri: http://example.org
        filters:
@@ -498,7 +499,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: rewritepath_route
        uri: http://example.org
        predicates:
@@ -545,7 +545,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: setpath_route
        uri: http://example.org
        predicates:
@@ -566,7 +565,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: setresponseheader_route
        uri: http://example.org
        filters:
@@ -585,7 +583,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: setstatusstring_route
        uri: http://example.org
        filters:
@@ -653,7 +650,6 @@ spring:
  cloud:
    gateway:
      routes:
-      # =====================================
      - id: setstatus_route
        uri: http://example.org
        filters:
--- a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java
+++ b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/config/GatewayAutoConfiguration.java
@@ -327,8 +327,8 @@ public class GatewayAutoConfiguration {
 	@ConditionalOnClass({HystrixObservableCommand.class, RxReactiveStreams.class})
 	protected static class HystrixConfiguration {
 		@Bean
-		public HystrixGatewayFilterFactory hystrixGatewayFilterFactory() {
-			return new HystrixGatewayFilterFactory();
+		public HystrixGatewayFilterFactory hystrixGatewayFilterFactory(DispatcherHandler dispatcherHandler) {
+			return new HystrixGatewayFilterFactory(dispatcherHandler);
 		}
 	}

--- a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixGatewayFilterFactory.java
+++ b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/HystrixGatewayFilterFactory.java
@@ -17,6 +17,7 @@

 package org.springframework.cloud.gateway.filter.factory;

+import java.net.URI;
 import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
@@ -24,8 +25,11 @@ import java.util.function.Function;
 import org.springframework.cloud.gateway.filter.GatewayFilter;
 import org.springframework.cloud.gateway.filter.GatewayFilterChain;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.tuple.Tuple;
+import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.server.ServerWebExchange;
+import org.springframework.web.util.UriComponentsBuilder;

 import com.netflix.hystrix.HystrixCommandGroupKey;
 import com.netflix.hystrix.HystrixCommandKey;
@@ -34,6 +38,8 @@ import com.netflix.hystrix.HystrixObservableCommand.Setter;
 import com.netflix.hystrix.exception.HystrixRuntimeException;

 import static com.netflix.hystrix.exception.HystrixRuntimeException.FailureType.TIMEOUT;
+import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_REQUEST_URL_ATTR;
+import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.containsEncodedQuery;
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.setResponseStatus;

 import reactor.core.publisher.Mono;
@@ -46,30 +52,58 @@ import rx.Subscription;
 */
 public class HystrixGatewayFilterFactory implements GatewayFilterFactory {

+	public static final String FALLBACK_URI = "fallbackUri";
+
+	private final DispatcherHandler dispatcherHandler;
+
+	public HystrixGatewayFilterFactory(DispatcherHandler dispatcherHandler) {
+		this.dispatcherHandler = dispatcherHandler;
+	}
+
 	@Override
 	public List<String> argNames() {
 		return Arrays.asList(NAME_KEY);
 	}

+	@Override
+	public boolean validateArgs() {
+		return false;
+	}
+
 	@Override
 	public GatewayFilter apply(Tuple args) {
 		//TODO: if no name is supplied, generate one from command id (useful for default filter)
-		final String commandName = args.getString(NAME_KEY);
-		return apply(commandName);
+		String commandName = args.getString(NAME_KEY);
+		if (args.hasFieldName(FALLBACK_URI)) {
+			URI fallbackUri = URI.create(args.getString(FALLBACK_URI));
+			if (!"forward".equals(fallbackUri.getScheme())) {
+				throw new IllegalArgumentException("Hystrix Filter currently only supports 'forward' URIs, found "+ fallbackUri);
+			}
+			return apply(commandName, fallbackUri);
+		}
+		return apply(commandName, null);
 	}

 	public GatewayFilter apply(String commandName) {
+		return apply(commandName, null);
+	}
+
+	public GatewayFilter apply(String commandName, URI fallbackUri) {
 		final HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey(getClass().getSimpleName());
 		final HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey(commandName);

 		final Setter setter = Setter.withGroupKey(groupKey)
 				.andCommandKey(commandKey);
-		return apply(setter);
+		return apply(setter, fallbackUri);
 	}

 	public GatewayFilter apply(Setter setter) {
+		return apply(setter, null);
+	}
+
+	public GatewayFilter apply(Setter setter, URI fallbackUri) {
 		return (exchange, chain) -> {
-			RouteHystrixCommand command = new RouteHystrixCommand(setter, exchange, chain);
+			RouteHystrixCommand command = new RouteHystrixCommand(setter, fallbackUri, exchange, chain);

 			return Mono.create(s -> {
 				Subscription sub = command.toObservable().subscribe(s::success, s::error, s::success);
@@ -89,18 +123,43 @@ public class HystrixGatewayFilterFactory implements GatewayFilterFactory {

 	//TODO: replace with HystrixMonoCommand that we write
 	private class RouteHystrixCommand extends HystrixObservableCommand<Void> {
+
+		private final URI fallbackUri;
 		private final ServerWebExchange exchange;
 		private final GatewayFilterChain chain;

-		RouteHystrixCommand(Setter setter, ServerWebExchange exchange, GatewayFilterChain chain) {
+		RouteHystrixCommand(Setter setter, URI fallbackUri, ServerWebExchange exchange, GatewayFilterChain chain) {
 			super(setter);
+			this.fallbackUri = fallbackUri;
 			this.exchange = exchange;
 			this.chain = chain;
 		}

 		@Override
 		protected Observable<Void> construct() {
-			return RxReactiveStreams.toObservable(this.chain.filter(this.exchange));
+			return RxReactiveStreams.toObservable(this.chain.filter(exchange));
+		}
+
+		@Override
+		protected Observable<Void> resumeWithFallback() {
+			if (this.fallbackUri == null) {
+				return super.resumeWithFallback();
+			}
+
+			//TODO: copied from RouteToRequestUrlFilter
+			URI uri = exchange.getRequest().getURI();
+			boolean encoded = containsEncodedQuery(uri);
+			URI requestUrl = UriComponentsBuilder.fromUri(uri)
+					.host(null)
+					.port(null)
+					.uri(this.fallbackUri)
+					.build(encoded)
+					.toUri();
+			exchange.getAttributes().put(GATEWAY_REQUEST_URL_ATTR, requestUrl);
+
+			ServerHttpRequest request = this.exchange.getRequest().mutate().uri(requestUrl).build();
+			ServerWebExchange mutated = exchange.mutate().request(request).build();
+			return RxReactiveStreams.toObservable(HystrixGatewayFilterFactory.this.dispatcherHandler.handle(mutated));
 		}
 	}
 }
--- a/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/builder/GatewayFilterSpec.java
+++ b/spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/route/builder/GatewayFilterSpec.java
@@ -103,6 +103,14 @@ public class GatewayFilterSpec extends UriSpec {
 		return filter(getBean(HystrixGatewayFilterFactory.class).apply(setter));
 	}

+	public GatewayFilterSpec hystrix(String commandName, URI fallbackUri) {
+		return filter(getBean(HystrixGatewayFilterFactory.class).apply(commandName, fallbackUri));
+	}
+
+	public GatewayFilterSpec hystrix(HystrixObservableCommand.Setter setter, URI fallbackUri) {
+		return filter(getBean(HystrixGatewayFilterFactory.class).apply(setter, fallbackUri));
+	}
+
 	public GatewayFilterSpec prefixPath(String prefix) {
 		return filter(getBean(PrefixPathGatewayFilterFactory.class).apply(prefix));
 	}
--- a/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/HystrixGatewayFilterFactoryTests.java
+++ b/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/HystrixGatewayFilterFactoryTests.java
@@ -17,6 +17,9 @@

 package org.springframework.cloud.gateway.filter.factory;

+import java.util.Collections;
+import java.util.Map;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.boot.SpringBootConfiguration;
@@ -24,18 +27,14 @@ import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.cloud.gateway.test.BaseWebClientTests;
 import org.springframework.context.annotation.Import;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.web.reactive.function.client.ClientResponse;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;

-import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
-import static org.springframework.cloud.gateway.test.TestUtils.assertStatus;
-
-import reactor.core.publisher.Mono;
-import reactor.test.StepVerifier;

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = RANDOM_PORT)
@@ -44,40 +43,39 @@ public class HystrixGatewayFilterFactoryTests extends BaseWebClientTests {

 	@Test
 	public void hystrixFilterWorks() {
-		Mono<ClientResponse> result = webClient.get()
-				.uri("/get")
+		testClient.get().uri("/get")
 				.header("Host", "www.hystrixsuccess.org")
-				.exchange();
-
-		StepVerifier.create(result)
-				.consumeNextWith(
-						response -> {
-							assertStatus(response, HttpStatus.OK);
-							HttpHeaders httpHeaders = response.headers().asHttpHeaders();
-							assertThat(httpHeaders.getFirst(ROUTE_ID_HEADER))
-									.isEqualTo("hystrix_success_test");
-						})
-				.expectComplete()
-				.verify(DURATION);
+				.exchange()
+				.expectStatus().isOk()
+				.expectHeader().valueEquals(ROUTE_ID_HEADER, "hystrix_success_test");
 	}

 	@Test
 	public void hystrixFilterTimesout() {
-		Mono<ClientResponse> result = webClient.get()
-				.uri("/delay/3")
+		testClient.get().uri("/delay/3")
 				.header("Host", "www.hystrixfailure.org")
-				.exchange();
+				.exchange()
+				.expectStatus().isEqualTo(HttpStatus.GATEWAY_TIMEOUT);
+	}

-		StepVerifier.create(result)
-				.consumeNextWith(
-						response -> assertStatus(response, HttpStatus.GATEWAY_TIMEOUT))
-				.expectComplete()
-				.verify(DURATION);
+	@Test
+	public void hystrixFilterFallback() {
+		testClient.get().uri("/delay/3?a=b")
+				.header("Host", "www.hystrixfallback.org")
+				.exchange()
+				.expectStatus().isOk()
+				.expectBody().json("{\"from\":\"fallbackcontroller\"}");
 	}

 	@EnableAutoConfiguration
 	@SpringBootConfiguration
 	@Import(DefaultTestConfig.class)
-	public static class TestConfig { }
+	@RestController
+	public static class TestConfig {
+		@RequestMapping("/fallbackcontroller")
+		public Map<String, String> fallbackcontroller(@RequestParam("a") String a) {
+			return Collections.singletonMap("from", "fallbackcontroller");
+		}
+	}

 }
--- a/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/ForwardTests.java
+++ b/spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/ForwardTests.java
@@ -57,9 +57,7 @@ public class ForwardTests {

 	@Test
 	public void forwardWorks() {
-		this.client
-				.get()
-				.uri("/localcontroller")
+		this.client.get().uri("/localcontroller")
 				.header(HttpHeaders.HOST, "www.forward.org")
 				.exchange()
 				.expectStatus().isOk()
--- a/spring-cloud-gateway-core/src/test/resources/application.yml
+++ b/spring-cloud-gateway-core/src/test/resources/application.yml
@@ -60,7 +60,7 @@ spring:

      # =====================================
      - id: forward_test
-        uri: forward:///localcontroller
+        uri: forward:/localcontroller
        predicates:
        - Host=**.forward.org

@@ -72,6 +72,17 @@ spring:
        filters:
        - Hystrix=failcmd

+      # =====================================
+      - id: hystrix_fallback_test
+        uri: ${test.uri}
+        predicates:
+        - Host=**.hystrixfallback.org
+        filters:
+        - name: Hystrix
+          args:
+            name: fallbackcmd
+            fallbackUri: forward:/fallbackcontroller
+
      # =====================================
      - id: hystrix_success_test
        uri: ${test.uri}